@book{13823,
	author = {Singh, R. P. and Sapre, S D, jt. auth.},
	title = { Communication systems :},
	publisher = {Tata McGraw-Hill,},
	year = {c2007 [Reprinted 2009].},
	address = {New Delhi :},
	edition = {2nd ed. , Indian Reprint ed.}
}